Problem: If $x \odot y = 3x-4$ and $x \boxdot y = 3x^{2}-y^{2}$, find $-3 \odot (-5 \boxdot -4)$.
Solution: We don't need to find $-5 \boxdot -4$ because $x \odot y$ depends only on the left operand. Find $-3 \odot y$ $ -3 \odot y = (3)(-3)-4$ $ \hphantom{-3 \odot y} = -13$.